Biomass availability, logistics and cost

From the analysis on biomass availability in European regions best candidates for application in steel indus- try are biomass from forest and wood industry and agricultural residues.

From recent literature the potential supply of forest residues and forest industry by-products can be deduced [4, 5].

The energy potential of wood fuel in EU is estimated to around 1300 PJ/year. A large number of data on biomass availability are reported in terms of energy (it can be assumed the equivalence 1 t biomass ~ 10 GJ, or 1Mt ~ 10PJ).

In EU15, agriculture is the most important land use in geographic terms occupying 40% (130 million ha) of the total land area (323 million ha).

Also Europe is one of the world’s largest and most productive suppliers of food and fibre with the Euro- pean Union accounting alone for 10% of the global cereal production and 16% of global meat produc- tion.

The total resource potential of agricultural crop resi- dues has been estimated to 1064 PJ/year for EU and 306 PJ/yr for the Accession countries.

Classifications of available biomass country by coun- try are available [5].

A number of logistic requirements must be satisfied for a realistic industrial use.

The biomass supply logistics is characterized by a wide area distribution of biomass; time and weather- sensitive crop maturity; variable moisture content; low bulk density of biomass material and a short time window for collection with competition from concurrent harvest operations.

The analysis carried out in the first phase of ULCOS project showed that a supply cost around 3 €/GJ can be foreseen and a straw density of 3-5 t/hectare are required.

In the case of biomass used for DRI process (at least 1 Mt/year), according to the results of the process models the biomass availability must be at least 650 kt/year.

The analysis carried out in the first phase of ULCOS project showed that to maintain the supply cost at an acceptable level, a distance from the DRI plant of max 50 km must be considered.

Areas with these biomass concentration are present in several region of Europe, most of which currently have not a real biomass employment policy.

Specific studies are available to evaluate logistic aspects and their impact on economic balance of substitution of fossil fuel with biomass.

An Italian study [6], carried out on the province of Cremona, is based on a total of 226 kt/year of bio- mass.

T. Buergler and A. Di Donato

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It takes into account the costs for collection of agri- cultural residues, culture of short rotation forestry, transport and transformation (including construction, management and maintenance of power plants)

An important output of the study is the optimisation of number and distribution of localisations of the plants for biomass collection and pre-treatment in view of a final utilization in a single power plant

Cost estimation for biomass are carried out on the basis of:

•

Cost for collection or production

•

Preparation

•

Transport

•

Quality (mainly calorific value)

In the context of energy generation several studies are available concerning cost evaluation[7].

ENEL, the main Italian electrical energy company, has produced several studies about use and cost of biomass for energy production, taking into account also logistic aspects [8,9].

Table 1 summarizes main figures used for estimating the cost of pellets and chips from wood industry and agricultural residues, on the basis of physical charac- teristics [9].

Low Calorific

~10MJ/kg

~16MJ/kg

~12MJ/kg

Value

~3.3 GJ/m3

~11.2 GJ/m3

~2.6 GJ/m3

Properties

Pellet

Chips

Agriculture residues

Density

250-400 kg/m3

600-700 kg/m3

15-300 kg/m3

Humidity

40-55%

8-12%

30%

Size

1÷100 mm

6÷12 mm

~60 €/t

160÷180 €/t

30÷50 €/t

Price

~6 €/GJ

~10,6 €/GJ

~3.8 €/GJ

Table 1. Characteristics and prices of three type of biomass.

Wood industry residues

The final price of biomass depends on the material quality and transport. This second aspect is ex- tremely variable, due to the large fluctuations of oil and fuels prices.

At the begin of the 2008 a transport cost of the order of 0,05-0,10 €/t per km was estimated, increasing the prize of 10-30% (biomass collected in a radius of 50 km).